[DanElam]

Most of instructors use a motorcycle intercom that slides under your helmet. I use this when I take passengers in the Cobra (on the track) or when I instruct in an open car. I use it a lot in regular cars too. They are less than $100 and work pretty well.

I have done open top communication a handful of times without the intercom. In those situations, you and the instructor should review hand signals. I use left, right, brake, modulate throttle, throttle, and caution (yellow, red, black flag). Another instructor taught me to use these and now I usually use them even when I have the intercom. In many ways, the visual cues help reinforce what I am saying on the intercom.

Of course, every once in a while I get some idiot student who won't listen. I once had a south american rally car driver. He had terrific car control, but kept overdriving the yellows. Sigh. We had to come in for an attitude adjustment.

-Dan